The invention relates to a self-supporting heliothermal flat collector module that includes:                A sheet metal panel,        A register-type arrangement of capillary tubes separated from one another for the flow of a fluid medium that lies on the rear side of the sheet metal panel opposite that to be irradiated, and        A thermally-insulating insulation core also positioned on the rear side.        
A flat collector module of this type is known from DE-PS 100 43 295. This patent basically provides for the capillary tubes to be attached to the sheet metal panel by means of surface spraying with fluid metal particles. An adhesive connection of the sheet metal panel configured with the capillary tubes to the foam insulation core may also be taken from DE-PS 100 43 295, but in any case, the details of the adhesive connection are not specified.
Such an adhesive connection presents a technical problem in heliothermic flat collector modules since the joining parts possess varying elasticity modules, and thus multi-axis tension components may arise. In particular, the sheet metal panel exposed to solar irradiation may be strongly warmed and deformed. Resultantly, the adhesive connection may be at least partially destroyed, and the contact between the capillary tubes and the sheet metal panel may be interrupted.